The present invention refers to a new type of explosive attachment device, which is suitable for being used for mounting of different mechanical components, thus that the joint if needed can be severed immediately by means of detonation In such a manner that the very detonation will not be a risk of accidents for human beings or animals.
The explosive bolt described above is appropriate for being used for such connections, which have to be openable rapidly due to an emergency situation. A large field of such use is for Instance for mounting of vehicle doors and the new device is particularly useful for this purpose. Nowadays door hinge systems both for passenger cars and for lorries are constructed so, without exception, that it at a somewhat more violent collision is an evident risk, that vehicle doors get stuck, as a heavy demolition of the car body will compress doors as well as door openings. The axes of the hinges might also loose their parallelism and door locks can be damaged, and all this taken together can make opening of the car doors more difficult or even impossible after a violent collision, which in turn can cause dangerous situations of different degrees for passengers. Outer circumstances can also worsen accidental situations. Such an example is when a car turns over and possible obstacles at the ground such as rocks, ditches, different types of large objects, etcetera, can prevent the car doors from being opened. Furthermore it is also usual that passengers loose consciousness and it is then even more difficult for the rescue team to help them to come out of the vehicle.
The explosive charge In an explosive attachment device must be strong enough for causing the desired effect to separate the connected components, but this also leads to undesired side effects. If the device is constructed so, that it will be blasted completely to pieces, it is easy that there as a result is dangerous metal splinters, and also small volumes of appropriate explosive, which is commonly used in such circumstances, cause considerable force at the detonation, which can result in that the metal splinters will have a high velocity, which therefore have a large possibility of penetrating through the typical thin sheet metal structures, which are common in car bodies and therefore the passengers are subjected to danger. The chock effect of the detonation is also undesired and means a risk e.g. for impaired hearing to the passengers. Furthermore the handling of the explosive components must be considered In connection to storing and transport and also at the time of production of the cars, and in case of a possible unintended detonation, the risk for personal injuries must be minimized.
There are a number of known proposals for explosive attachment devices In form of different versions of explosive bolts, which principally could be used for assembly of car door hinges in order to reduce the problems described above In connection to accidents. Such proposals are disclosed for Instance In: U.S. Pat. No. 5,997,230, U.S. Pat. No. 3,754,496, U.S. Pat. No. 2,653,504, U.S. Pat. No. 3,582,017, U.S. Pat. No. 1,400,401 and DE 2203470. These proposals are anyhow intended to be used primarily within space travel technology and for military use and for both these fields of use there are basically other conditions than for cars and for that reason the known solutions are not suited for mounting of car doors. In space travel persons are not directly subjected to detonations of explosive bolts with metal splinters, which is the case in cars. Within the military field, explosive bolts are e.g. used in mines and missiles and the like and the situation is quite the opposite, as any splinter may even be desirable.
It can furthermore be established that in the proposals mentioned above, the detonation takes place substantially immediately after Initiation, without any time delay at all, and this is an impossible situation in respect of mounting of car doors with aid of explosive bolts. At a violent collision the cars are often making a passage through the air with tumbling motion and it Is evident, that a loosening of the doors at a too early stage, could be nearly a catastrophe. The car must come to a stop and its position must be stabilized before it Is time for the doors to be separated by detonation of any type of door hinge attachment.